back panel of computer

AC /OFF SWITCH 

Main AC supply on/off switch, this switch is attached to main SMPS. 

POWER SOCKET 

main AC supply connect to this socket through ac power cord.

EXHAUST FAN 

it is used to cool the SMPS 

Mouse and key board 

The standard PS/2 mouse/keyboard DIN connectors is for a PS/2 mouse or key board. PS/2 mouse connector is green colour 6 pin female, and purple color 6 pin female connector for key board.

parallel port 

A parallel port is a standard printer port that supports enhanced parallel port (EPP) and extended capabilities parallel port (ECP) mode. it is pink colour 25 pin female connector.

serial port

The serial port is a 16550 a high speed communications port that sends/receives 16 bytes FIFOs.

you can attach a serial mouse or other serial devices like modem directly to the connector.

 D- sub port or VGA port

 The d-sub port supports  a 15- pin D - SUB connect a monitor the DB 15-pin female connector is provided for monitor.

DVI PORT 

The  DVI digital visual interface connector allows you to connect an LCD monitor.it provides a high-speed digital interconnection between the computer and its display device.to connect an LCD monitor, simply plug your monitor cable into the DVI connector, and make sure that the other end of the cable is properly connected to your monitor.

DVI connector does not support connecting the D-sub to DVI connector.

LAN

THE STANDARD rj 45 LAN jack is for connection to the local area network. you can connect a network cable to it.

activity LED is orange colour, 

when internet or lan connection established that ORANGE COLOUR LED BLINKING IT INDICATES DATA TRANSMISSION or receiving is occurring. the computer is communicating with another computer on the lan.

conncetion speed led

If orange lit glow that means 1Gbps data rate, or green lit glows internet connection speed upto 100Mbps only. if led not glow means it is only 10Mbps only.

 USB

 the USB port supports the USB 3.0/ 2.0/1.1 specification. universal serial is for attaching USB devices such as keyboard , mouse, or other USB - compatible devices.